While hiking in Calabasas with a friend on Monday, Britney Spears brought out the big nips ... saucers ... headlights ... areolas ... boobs ... umm ... bodyguard.

And boy does she look about as happy as if someone just told her Cheetos and KFC were partnering to make a Flamingo Hot Cheetos-crusted fried chicken sandwich!

That's all ye know on earth, and all ye need to know ...